I. Diagnostic principles
The diagnosis of osteoporosis is based on the reduction of bone mineral density, and the diagnosis of primary osteoporosis can be made with reference to medical history, biochemistry and fracture.
Second, the basic means
1, to determine the reduction of bone mineral density as far as possible by the combination of bone mineral content and spinal radiographs, this standard is currently mainly based on DXA (dual-energy X-ray absorption method) as a means to develop.
The current standard is mainly based on DXA (dual-energy X-ray absorption method) as a means to develop, does not exclude the application of a variety of methods.
2.Units that do not have bone densitometer can use X-rays for the initial diagnosis of osteoporosis, generally used in the spine, but also the femoral neck, heel bone, tubular bone X-rays.
C. Diagnostic and grading criteria for bone mineral content (mainly used for female adults, male reference implementation)
11 After discussion in this meeting, refer to the World Health Organization (WHO) standards, combined with China’s national conditions, based on race, gender, regional peak bone volume (mean value of M ):
> M – 1SD normal
M – 1SD to 2SD decreased bone mass
M – 2SD osteoporosis (mild and moderate according to the requirements of diagnosis and treatment)
M – 2SD with one or more fractures, severe osteoporosis
21 Referring to the Japanese standard modified in 1996, if you have not done peak BMD survey, or if you have done some survey, but SD is not convenient to apply, you can use the diagnosis method of percentage of bone loss (%).
> M – 12% Normal
M – 13% to 24% Bone loss
M – 25% osteoporosis (classified as mild or moderate according to the requirements of diagnosis and treatment)
M – 25% Severe osteoporosis with one or more fractures
Diagnostic requirements of X-rays
1. Photo quality: Except for the heel bone, which should be photographed in lateral position only, other parts of the bone structure should be photographed in ortho position. The clarity, contrast and detail of the photograph should be high, and the hierarchical structure of soft tissue and bone tissue should be clear.
2, vertebral bone density estimation, the following methods are recommended: degree I longitudinal trabeculae are obvious; degree II longitudinal trabeculae become sparse; degree III longitudinal trabeculae are not obvious; the same occurrence of compression fracture, the wedge index should be measured. Wedge index = (anterior height of vertebral body – posterior height)/posterior height
3. The femoral neck can be measured using the Singh index method. It is defined as osteoporosis below degree III.
4.The Jham ar ia index of the heel bone is defined as suspicious in degree III and osteoporosis in degree III or below.
5.The tubular cortical index method is commonly used in the long bones of the limbs, the second metacarpal bone and the clavicle, etc. The cortical index = cortical thickness at the midpoint / transverse diameter of the bone at that point; index < 0,4 is considered suspicious, < 0,35 is diagnosed as osteoporosis.
Annexes
I. Definition of Osteoporosis (OP)
Primary osteoporosis is a systemic bone disease characterized by a decrease in bone mass and degradation of the microstructure of bone tissue, resulting in increased bone fragility and increased risk of fracture.
Understanding of the definition of OP: ①Bone loss: it should include the reduction of bone mineral and its matrix in equal proportion. (2) Bone microstructure degeneration: due to imbalance of bone tissue resorption and formation, manifested by destruction, thinning and fracture of bone trabecular structures. ③Bone brittleness increases, bone mechanical strength decreases, fracture risk increases, and microfracture or complete fracture easily occurs due to reduced load bearing capacity. Lumbar compression fractures may occur silently, or fractures of the distal radius, proximal femur, and upper humerus may occur with little external force.
II. Reasons for diagnosing osteoporosis by the percentage method
1. The diagnostic criteria expressed in SD are suitable for the lumbar spine, and the sites other than the lumbar spine (such as the radius, second metacarpal, femoral neck, and heel bone) need to be changed. When expressed in %, the standard is the same for all parts.
2.The percentage method is easier to understand than the SD method, and it is simple to use.
Classification of osteoporosis:
Type I primary osteoporosis: Type I postmenopausal osteoporosis; Type II senile osteoporosis.
Secondary osteoporosis: A endocrine diseases; B myeloproliferative diseases; C drug-related bone loss; D nutritional deficiency diseases; E chronic diseases (obvious parenchymal organ diseases, connective tissue diseases); F congenital diseases; G disuse bone loss; H other diseases and factors that can cause secondary osteoporosis.
The third category of idiopathic osteoporosis: A adolescent osteoporosis; B light-aged adult osteoporosis.
Fourth, the differential diagnosis of primary osteoporosis
1.Secondary osteoporosis
2, other diseases with low bone mass: a, various osteochondrosis (calcium and vitamin D deficiency, renal tubular acidosis, etc.); b, primary and secondary hyperthyroidism; c, bone metastases of malignant tumors; d, multiple myeloma; e, spinal hemangioma; f, septic spondylitis; g, others.
V. Uniform technical methods
Units participating in the diagnostic criteria study of bone density survey should unify the technical methods:
1, unified design of the questionnaire and checklist
2, accuracy by the unit with the instrument, once a day in the morning BMD of the body model, 5 consecutive days to find the CV (coefficient of variation)
3. The accuracy of the instrument was calibrated by a uniform body model, and those who failed to achieve it were corrected by a factor.
4. Uniform data analysis of fracture thresholds (the slices of each unit were returned after centralized use).
5. Standardization of measurement methods and exclusion of unfavorable factors. 1) Anyone with one of the following conditions will not participate in the measurement of BMD: scoliosis deformity, hunchback, spinal surgery, spinal labral hyperplasia, spinal trauma compression, systemic parenchymal organ obvious disease (including endocrine disease). 2) For those who participate in the diagnostic criteria for measuring bone density, both the lumbar spine and the femoral neck should be measured. In addition to the required fixed measurement of the femoral neck, a sandbag should be added to the lateral side of the foot for compression to ensure 15 degrees of internal rotation of the femur.